1. Technical Field
The present invention relates to a developer apparatus which comprises a toner carrier roller whose surface carries toner, and an image forming apparatus for and an image forming method of developing an electrostatic latent image with toner using this roller.
2. Related Art
In techniques for developing an electrostatic latent image carried on an image carrier with toner, an apparatus is widely used which includes a toner carrier roller which is shaped approximately like a cylinder, carries toner on a surface thereof, and is arranged opposed facing the image carrier. For the purpose of improving the characteristics of toner carried on the surface of such a toner carrier roller, the applicant of the present application has earlier disclosed a structure of a toner carrier roller having a cylindrical shape that the surface of the roller includes convex sections which are regularly arranged and a concave section which surrounds the convex sections (JP-A-2007-121949). Since the concavo-convex patterns in the surface are regulated and uniform, such a structure is advantageous in that it permits easy control of the thickness of a toner layer which is carried on the surface of the roller, the charge level and the like.
In an image forming apparatus having the structure above, for the purpose of restricting the thickness of a toner layer carried by the convex and the concave sections formed in the toner carrier roller to a predetermined thickness, a layer thickness restricting member (restriction blade) abuts on the toner layer which is on the surface of the toner carrier roller.